New Utilization Technology: Producing Compound Amino Acids from Sewage Sludge by Acid Hydrolysis
In this study, a new and effective utilization technology for waste activated sludge (WAS) has been employed to produce compound amino acids. The process was achieved by two-step hydrochloric acid (HCl) hydrolysis of sewage sludge (SS). Firstly, the SS was hydrolyzed for proteins by HCl under high temperature and pressure in self-made hydrolysis reactor. And the effects of the hydrolytic temperature, time and pH on the extraction ratio of proteins were investigated in detail. The results show that the best extraction efficiency of proteins is obtained at a pH= 0.5, T=121 ℃ and a reaction time of 5 h, under which condition, the protein extraction ratio is the highest of 78.5% (38.2% of initial dry WAS weight), and the DS weight reduces about 45.4%. Then the sludge proteins were hydrolyzed for compound amino acids by HCl and the compound amino acids produced were extracted by ion-exchange resin method. Major technological parameters such as the HCl loading, hydrolytic time and temperature on the hydrolysis efficiency were investigated in detail. And the optimum condition for protein hydrolysis was as follows: T=110-120 ℃, hydrolytic time=10 h, hydrochloric acid (mL) /dry WAS (g) ratio is 8:1. Under this condition, the amino acids yield were 10.7-12.2 (g amino acids)/(100 g WAS) and the extraction ratio of amino acid was high to 80.9%. This novel utilization technology of WAS is environmentally friendly and economically feasible, which can provide an abundant resource of amino acids.
sewage sludge compound amino acids acid hydrolysis proteins
KONG Sifang LIU Yangsheng ZENG Hui WANG Junjian ZHONG Xiuping
College of Environment and City,Peking University Shenzhen Graduate School,the Key Laboratory Circular Economy,Shenzhen 518055,Guangdong,China
国际会议
2009 International Symposium on Environmental Science and Technology(2009环境科学与技术国际会议)
上海
英文
2324-2330
2009-06-02（万方平台首次上网日期，不代表论文的发表时间）